Refactor MethodHandler/MethodKey/MethodCache to be ClassLoader awared

• Type: Story
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.1.1 CE GA2, 6.1.20 EE GA2, 6.2.0 CE M2
• Fix Version/s: 6.1.30 EE GA3, 6.2.0 CE B1
• Component/s: Core Infrastructure, Fault Tolerance > Clustering Framework, Fault Tolerance > Portlet Sandboxes, Portal Services, Portal Services > Component Management
• Labels: None
• Branch Version/s:
  6.1.x
• Backported to Branch:
  Committed
• Epic/Theme:
  • Platform
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/7539

This classloader awareness is critical Portal <> Plugin and Plugin <> Plugin across classloader invocation and cluster/portal resiliency RPC framework.